Lip pleomorphic adenomas: case series and literature review

Background: Pleomorphic adenoma (PA) is the most frequent benign salivary gland tumor, but a lip PA is rare. Although this tumor may be definitively diagnosed by imaging or a tissue biopsy if it is reasonably large, PAs on the lip are relatively small, and they present findings that are similar to those of other lip lesions, which can make a preoperative diagnosis difficult. Methods: We analyzed all PAs in the oral region and lesions on the lips treated in our department over the past 20 years, and we discuss them together with the relevant literature. Results: We found that 11.8% (n=6) of the PAs occurred on a lip (upper lip: 9.8%, lower lip: 2.0%), and ~1% of all mass lesions of the lips were PAs. The average size of the lip PAs was 1.5±0.7 cm (range, 0.7–2.2 cm). For preoperative diagnostic assistance, ultrasonography (US) (n=4), magnetic resonance (MR) (n=3), or no imaging (n=2) was used. An excisional biopsy was performed in all cases, and to date, no recurrence or malignant transformation has been observed. Conclusions: Lip PA is relatively rare. Because almost all of these lesions are small, a preoperative diagnosis is more difficult compared to palatal lesions. This tumor is also prone to long-term neglect and has the potential for recurrence and malignant transformation. It is thus necessary to perform an excision that includes the capsule and surrounding tissues, and careful postoperative follow-up should be continued

Reproduction of the Antitumor Effect of Cisplatin and Cetuximab Using a Three-dimensional Spheroid Model in Oral Cancer

Background/Aim: Cancer research has been conducted using cultured cells as part of drug discovery testing, but conventional two-dimensional culture methods are unable to reflect the complex tumor microenvironment. On the other hand, three-dimensional cultures have recently been attracting attention as in vitro models that more closely resemble the in vivo physiological environment. The purpose of this study was to establish a 3D culture method for oral cancer and to verify its practicality. Materials and Methods: Three-dimensional cultures were performed using several oral cancer cell lines. Western blotting was used for protein expression analysis of the collected cell masses (spheroids), and H-E staining was used for structural observation. The cultures were exposed to cisplatin and cetuximab and the morphological changes of spheroids over time and the expression changes of target proteins were compared. Results: Each cell line formed spheroidal cell aggregates and showed enhancement of cell adhesion molecules over time. H-E staining showed tumor tissue-like structures specific to each cell line. Cisplatin showed concentration-dependent antitumor effects due to loss of cell adhesion and spheroid disruption in each cell line, while cetuximab exhibited antitumor effects that correlated with EGFR expression in each cell line. Conclusion: Spheroids made from oral cancer cell lines appeared to have tumor-like characteristics that may reflect their clinical significance. In the future, it may become possible to produce tumor spheroids from tissue samples of oral cancer patients, and then apply them to drug screening and to develop individualized diagnostic and treatment methods